Lingual Gingival Augmentation of Mandibular Implants.

Dental implants may require attached tissue to prevent peri-mucositis or peri-implantitis. When there is a lack of attached tissue at the mandibular lingual aspect of dental implants a free gingival graft may be done after careful consideration of anatomical structures.  An acryl stent may be used to protect the site from oral functioning.

Autogenous Dentin With Calcium Sulfate as Graft Material: A Case Series.

There have been recent reports of successful use of fragmented autogenous dentin being used as a graft material in implant dentistry. This may reduce morbidity and the need for a second donor site or for the use of alloplasts or allografts. This article discusses the background, preparation, and use of autogenous dentin as an oral osseous graft material. A series of cases where autogenous dentin is used to graft immediate dental implant sites is presented. After 21 months, one case biopsy showed only bone and no remnant dentin. Pulverized autogenous dentin may be an appropriate graft material in implant dentistry.

A CBCT Assessment of the Incidence and Location of the Lingual Foramen in the Anterior Mandible.

The purpose of this article is to assess the incidence of lingual foramina and associated vasculature in the anterior mandible to improve the understanding of their locations for dental implant placement. Intraoperative bleeding can be a significant complication. Presurgical assessment of the surgical site should be performed to identify anatomical landmarks. This can prevent a potential life-threatening hemorrhage that may compromise the airway. Nutrient canals can occur in the anterior mandible and have been reported to cause significant bleeding if violated. Using cone beam computerized tomography (CBCT), this study defines the anatomical locales in the mandible. CBCTs of 70 patients were obtained and examined for the presence of lingual foramina. The distance of lingual foramina to the inferior border of the mandible, bifurcations, and propensity for the midline were assessed. Lingual foramina were found in all of the examined mandibles with variable configurations. CBCT may be important in planning for surgical procedures in the anterior mandible to prevent an unexpected hemorrhage. The present study is limited by its sample size, method of assessment, and confinement to a geographical population. The results will need validation in further studies, which may incorporate multiple assessment techniques and a larger sample size to include greater geographical distribution. Future work may seek to describe emanations of the terminus of the sublingual artery.

Improving and calibrating channel erosion simulation in the Water Erosion Prediction Project (WEPP) model.

The Water Erosion Prediction Project (WEPP) model has been widely used to assess the impacts of management practices and climate change on runoff and soil loss at both hillslope and watershed scales. However, the representation of channel erosion processes in WEPP has not been changed significantly since it was released. The current (WEPP v2012.8) and previous WEPP versions assume that channel input erodibility parameters are constant through time, which may lead to erroneous channel detachment predictions, especially for cropland with substantial tillage operations. In this research, the temporally constant values of channel erodibility and critical shear stress were replaced by daily updated values, using the same temporal erodibility and critical shear stress adjustments that are applied in hillslope profile simulations for rill detachment. Observed watershed-scale runoff and soil erosion data from six agricultural watersheds were used to calibrate and compare the WEPP model performance in simulating channel runoff volumes and soil losses before and after the modification. The research showed both WEPP v2012.8 and the modified WEPP model (WEPP_CE) could satisfactorily simulate event-based hydrology and soil erosion at the watershed outlets after calibration. The WEPP_CE model with temporally varying channel erodibility and critical shear stress values demonstrated improved representation of the physical processes in channel soil detachment. Continued improvement in the representation of channel erosion processes in WEPP and other process-based models is needed. The improved WEPP model can be used to evaluate the effectiveness of soil conservation practices on hydrology and erosion in further research.

Rationale for Mini Dental Implant Treatment.

Mini dental implants can be used to support crowns and partial and complete dentures in compromised edentulous sites. Lack of bone width or site length may be treated with mini implants. Mini implants have less percutaneous exposure and displacement that may reduce complications. Nonetheless, mini implants transmit about twice the load to the supporting bone, and thus, control of occlusal loading is important. In fixed prosthetics, rounded flat cusps, splinting, implant protective occlusal schemes, and placement only in dense bone sites are features of successful mini implant treatment. With removable prosthetics, multiple mini implants may be needed for appropriate retention and load resistance. Maxillary lateral incisor and mandibular incisor sites may be best suited for mini implant treatment. However, past research on dental implants has been directed at standard sized implants. While mini implants are indeed dental implants, they behave somewhat differently under functional load, and the clinician should be circumspect and very judicious in their use. This article is a mini review and not a systematic review. The topics covered are not pervasive because each would require a monograph or textbook for a complete discussion.

A Theoretical Iteration for Predicting the Feasibility for Immediate Functional Dental Implant Loading.

When planning an implant-supported restoration, the dentist is faced with surgical and prosthetic technical issues as well as the patient's expectations. Many patients wish an immediate solution to an edentulous condition. This may be especially true in the esthetic zone, and that zone is determined by the patient. The dentist may consider when it is feasible to load the supporting implants with definitive or provisional prosthetics. In this work, many parameters were theoretically assessed for inclusion: bone density, cortical thickness, insertion torque, parafunction, bite load capacity, number of implants under load, implant/crown ratio, implant diameter, and length. After assessment, the most influential parameters were selected. An iteration, using patient age, implant diameter, bite load capacity, and cortical thickness, is now presented to aid the implant dentist in determining the feasibility for immediate functional loading of a just-placed dental implant in a healed site. Extensive testing is required to develop this concept. According to this iteration, most immediate functional loaded implants would fail. A future refined and definitive formula may enable the clinician to safely and immediately functionally load an implant with a definitive prosthesis. For access to the applet, please go to https://implantloading.shinyapps.io/shiny_app/.

Osseous Remodeling Around Dental Implants.

Adequate bone remodeling may be a primary parameter for long-term successful complication-free dental implant treatment. A 1.8-mm osseous thickness around dental implants is thought to be the minimum thickness for adequate vasculature for osteocyte nutrition and function. A dental implant does not provide progenitor cells or angiogenic or osteogenic factors. Thus, the surrounding bone may need to have a 1.8-mm thickness to accommodate the vasculature necessary for nutrients for appropriate remodeling. Additionally, the 1.8-mm dimension may provide for mechanical load resistance. There is no evidence to illustrate the physiologic need for the 1.8-mm dimension. This dimension requirement is based on clinical outcome observations. Basic science research for bone survival around dental implants is needed.

Hoop stress and the conical connection.

Dental implant-abutment connection design has developed into the use of a conical, shank and socket connection between the implant abutment and fixture. The connection between these two elements is, in effect, a conical wedge that may exert lateral forces under load that may result in fracture of the coronal implant socket fixture walls. This study evaluated the axial loading on a conical connection and found that axial loads were well tolerated but off-axial loads were not. Fracture of the implant coronal socket fixture wall occurred under off-axial loading.

Heat generated during seating of dental implant fixtures.

Frictional heat can be generated during seating of dental implants into a drill-prepared osteotomy. This in vitro study tested the heat generated by implant seating in dense bovine mandible ramus. A thermocouple was placed approximately 0.5 mm from the rim of the osteotomy during seating of each dental implant. Four diameters of implants were tested. The average temperature increases were 0.075°C for the 5.7-mm-diameter implant, 0.97°C for the 4.7-mm-diameter implant, 1.4°C for the 3.7-mm-diameter implant, and 8.6°C for the 2.5-mm-diameter implant. The results showed that heat was indeed generated and a small temperature rise occurred, apparently by the friction of the implant surface against the fresh-cut bone surface. Bone is a poor thermal conductor. The titanium of the implant and the steel of the handpiece are much better heat conductors. Titanium may be 70 times more heat conductive than bone. The larger diameter and displacement implant may act as a heat sink to draw away any heat produced from the friction of seating the implant at the bone-implant interface. The peak temperature duration was momentary, and not measured, but this was approximately less than 1 second. Except for the 2.5-mm-diameter implants, the temperature rises and durations were found to be below those previously deemed to be detrimental, so no clinically significant osseous damage would be expected during dental implant fixture seating of standard and large-diameter-sized implants. A 2.5-mm implant may generate detrimental heat during seating in nonvital bone, but this may be clinically insignificant in vital bone. The surface area and thermal conductivity are important factors in removing generated heat transfer at the bone-implant interface. The F value as determined by analysis of variance was 69.22, and the P value was less than .0001, demonstrating significant differences between the groups considered as a whole.

Horizontal Alveolar Ridge Splitting and Expansion.

When considering placing dental implants in atrophic edentulous sites, there may be inadequate site width and little or no vertical bone loss. Any of several surgical procedures can augment these sites. Extracortical augmentation is done by applying graft material against the cortical bone. This technique expects progenitor cells to migrate outside the bony ridge's confines and form new bone. Another method entails ridge splitting and expansion to create space for osteogenesis and, when possible, implant placement. This may be a better method for horizontal ridge augmentation. The ridge is split, separating the facial and lingual cortices for a complete bone fracture. The patient's osseous cells can then migrate into the created space from the exposed medullary bone to form bone. The technique can be preferably performed flapless so the intact periosteum maintains a blood supply to ensure appropriate healing.

The bis-acryl stent.

When placing dental implants, there may be a surgical flap to reposition. The flap can be sutured or held in place with a stent that protects the flap and maintains its position and immobility. Use of a bis-acryl stent may be preferable to sutures or other materials in many cases. Bis-acryl is easily applied from an auto-mixing gun. Stents may be preferable to sutures in that there is no "wicking effect," where bacteria colonize the suture beneath the healing surgical wound. Additionally, many times there is no submucosa to suture to, and the sides of the wound may not allow appropriate flap positioning and immobility with sutures. In these situations an acryl stent may be placed for easy and proper flap positioning and healing.

Ridge expansion and immediate placement with piezosurgery and screw expanders in atrophic maxillary sites: two case reports.

Endosseous dental implants may require bone augmentation before implant placement. Herein is described an approach to edentulous ridge expansion with the use of piezosurgery and immediate placement of implants. This may allow for a shortened treatment time and the elimination of donor-site morbidity. Two cases are reported. This technique uses a piezoelectric device to cut the crestal and proximal facial cortices. Space is then created with motorized osteotomes to widen the split ridge. This technique allows for expansion of narrow, anatomically limiting, atrophic ridges, creating space for immediate implant placement. The facial and lingual cortices provide support with vital osteocytes for osteogenesis. The 2 patients presented had adequate bone height for implant placement but narrow edentulous ridges. In patient 1 at site #11, the ridge crest was 3.12 mm thick and was expanded to accept a 4.3 mm × 13 mm implant. The resulting ridge width was 8.88 mm, which was verified using cone beam computerized tomography (CBCT). In patient 2 at site #8 and site #9, the narrow ridge was expanded using the same technique to accept 2 adjacent 3.5 mm × 14 mm implants. The implants were restored to a functional and esthetic outcome.

Frailty and mini dental implants.

Patients who have been diagnosed as frail and have atrochic jaws may have a dramatic increase of quality of life with mini implant treatment for retention of a mandibular complete denture.

Fold-over flap technique for developing the facial gingival contour: a case report.

A dental implant surgical technique is described including a 12-mm fold-over of a facial flap and coapting the internal side of the folded flap with a 4-0 suture. The flap is pulled against a provisional crown with a sling-type suture during the implant uncovery stage and may decrease the risk for a poor esthetic facial gingival architectural outcome.

Jaw bite force measurement device.

We describe a cost-effective device that uses an off-the-shelf force transducer to measure patient bite force as a diagnostic aid in determining dental implant size, number of implants, and prosthetic design for restoring partial edentulism. The main advantages of the device are its accuracy, simplicity, modularity, ease of manufacturing, and low cost.

Extraction and replantation of a periapically infected tooth.

At times, an infected tooth that may be deemed unrestorable may be salvaged by atraumatic removal, an in-hand apicoectomy and retrograde seal, then replantation. This patient was referred to this author for an extraction and implant treatment of the maxillary left second premolar. After a discussion, the patient preferred to salvage the tooth if possible. The tooth was successfully atraumatically removed, and an in-hand apicoectomy and retrograde amalgam seal was placed. The tooth was immediately replaced into its socket and was stable. The occlusal surface was flattened to prevent and off axial loading. A bis-acryl brace was applied to the facial and lingual aspect to prevent an overload while the tooth was healing. The patient was admonished to maintain a soft diet. After 3 weeks, the braces were removed, and the tooth was found to be stable. After 8 weeks, the tooth was asymptomatic, and the patient was able to revert to her normal diet without pain. While extraction, placing an apical seal and replantation of teeth is not a new modality; nonetheless, clinicians may need to be reminded of this procedure to increase the number of options presented to patients.